Hepatic encephalopathy Flashcards
What are the causes of hepatic encephalopathy?
Severe liver failure, acute liver failure, PSS, hepatic lipidosis, cirrhosis
What is the function of ammonia and what can happen when levels rise too high?
GABA and glutamate production.
Unopposed GABA stimulation = neurological signs
What are the clinical signs?
Head pressing, seizure, ataxia, circling, hypersalivation, PUPD, urolithiasis, UTI
How are the urinary signs produced?
Hepatic uricase converts uric acid to allontoin. Reduces the production of urea, so there is less urea in the urine. Lose the ability to concentrate urine and get PUPD.
High ammonia can also cause urolithiasis (ammoniun urate crystals)
How can the diet be modified?
Low/restricted protein diet
When might a restricted protein diet be contraindicated?
Young animals that are still growing. Restricting the protein causes muscle catabolism which increases ammonia and can cause/exacerbate hepatic encephalopathy. Feed the highest amount that can be tolerated.
Use vegetable protein not animal e.g. tofu, cottage cheese
How can GI ammonia production be reduced?
Lactulose - decreases colonic pH and reduces the conversion of ammonium to ammonia
Ab (Ampicillin, Neomycin) - reduce amount of uricase producing bacteria in the gut. Not metronidazole as this can cause hepatic toxicty.
Describe IVFT in this case
Not Hartmanns as contains lactate.
0.9% NaCl spike with KCl (counteract hypokalaemia)
How would the seizures be controlled?
Immediate control = Diazepam
Propofol
